1. Field of the Invention
This invention relates generally to mounting assemblies of the type that may be employed to support electromagnetic transducers such as loudspeakers. More particularly, the invention relates to mounting assemblies that are adjustable relative to two axes. When employed to support a loudspeaker or other transducer, a mounting assembly of this type enables adjustment of the directivity of acoustical output.
2. Related Art
An electro-acoustical transducer such as a loudspeaker (or, more simply, a speaker) may be mounted to an assembly or frame that allows adjustment of the directivity of the loudspeaker. Such a mounting assembly is typically structured so that one or more portions of the assembly are movable relative to the other fixed portions. Typical examples of this type of mounting assembly include the well-known “eyeball” mounts and “omni-mounts,” which often are utilized to mount a loudspeaker in a ceiling. Typically, the loudspeaker is housed within a frame structure of the mounting assembly, and the frame structure has an opening through which sound waves produced from the loudspeaker propagate into an intended listening area. To protect the loudspeaker, and particularly the flexible diaphragm of the loudspeaker, as well as to improve the appearance of the mounting assembly, a grille covers the opening of the frame structure.
Adjustable mounting assemblies of this type are typically adjustable between on-axis and off-axis positions. At the on-axis position, the axis of the loudspeaker is oriented in the same direction as the axis of the supporting frame, such that sound waves are at least initially directed normal to the opening of the mounting assembly and to the grille, and thus normal to the surface of a ceiling or other structure to which the mounting assembly is mounted. At the off-axis position, resulting from adjusting the movable portion of the mounting assembly, the axis of the loudspeaker is oriented at some angle relative to the axis of the supporting frame, and thus also at an angle to the ceiling or other mounting surface.
Known adjustable mounting assemblies for loudspeakers have at least two serious disadvantages. First, to allow for movement of the loudspeaker, the loudspeaker typically must be positioned at a significant distance behind the grille. This configuration ensures that the loudspeaker or the portion of the frame supporting the loudspeaker does not come into contact with the grille, and that the grille does not limit the excursions of the oscillating diaphragm of the loudspeaker during operation. Because of the distance conventionally required between the loudspeaker and the grille, sound waves produced from the loudspeaker must travel a significant distance through the confines of the mounting assembly before passing through the grille and into the listening area. Consequently, many of the sound waves are reflected off the structural components of the mounting assembly, which degrades acoustic performance. Such reflections occur even when the loudspeaker is mounted at the on-axis position, again due to the distance between the loudspeaker and the grille. Second, when the loudspeaker is adjusted so as to be directed off-axis, the loudspeaker is actually pointed into the mounting assembly, thus engendering more instances of reflections and further degrading acoustic performance.
Therefore, a need exists for a mounting assembly for a loudspeaker that enables adjustment of the directivity of the loudspeaker while minimizing the degradation of acoustic performance due to, for example, internal reflections of sound waves off the mounting assembly.